Among the broad array of tobacco products offered on the market today there is a class of goods intended for oral administration which do not require combustion. Within this class are snus products, some of which are provided in a pouch-like format. Each individual unit of snus is portioned into a fleece material which is sealed shut to form a filled pouch. A plurality of such pouches are placed in a container and provided to consumers.
The technology and materials for forming pouches of snus are similar to those techniques used to form tea bags. In the standard procedure, a piece of packing equipment provides a tube of thermoreactive fleece which is sealed at a bottom end, An injection or directed burst of metered snus product is placed toward the closed end of the tube, and a heat seal is made in the fleece above the top of the snus portion. An additional metered amount of snus product is placed above the heat seal, and the process continues to form a tape with a plurality of doses of snus product contained lengthwise therein. A cutting means separates the tape into individual units by cutting along each heat seal, resulting in rectangular pouches of snus. This is a widespread method but variations are known in the art.
In some versions of portion snus, the finished product is a rectangular white fleece pouch with a portion of dark tobacco visible through the fleece. Due to the high moisture content of snus, and particularly when influenced by storage or packaging conditions, liquid can seep from the snus and result in dark or brown coloured spots on the fleece. At least one cause of spotting is moisture leach from tobacco during heat sealing of the fleece that forms the pouch. The current method also results particles of snus being caught in the heat seal itself, causing spotting along the seam and material waste due to rejected pouches.
Pouches with snus particles trapped in the sealed seams and pouches with spots are less aesthetically appealing for consumers who may regard such goods as damaged, defective, or otherwise not ideal for consumption. Furthermore, the cumbersome nature of moist snus which contributes to these problems and also poses challenges for manufacturing such as clogging and sticking during handling. Because of the commercial nature of the product, skilled persons have proposed various solutions to these problems.
One line of teachings has been directed at reducing the moisture in the snus, thereby reducing the likelihood of seepage or moisture migration which is a source of spotting. Reduced moisture snus also avoids certain problems with snus clumping in the packing machinery. U.S. Pat. No. 4,703,765 discloses a device for injecting snus via a fill tube into a tubular fleece, welding transverse seams in the fleece then severing the welded areas to provide a plurality of heat sealed snus portions. The reference teaches that the moisture contents of the snus must not exceed 30%. Since the end product should ideally have a moisture content of about 50%, the portioned fleece-wrapped snus is sprayed with liquid to remoisturize the product from the outside.
Other sources have taught that because the heating of moist snus during the heat sealing process that forms the pouches is the contributory factor to spotting, this step should be reengineered or avoided. For example, RCD 000019328-0001 shows a snus pouch design in which a heat seal can be made along a portion of the fleece that is at a distance from the snus, then the sealed seam can be folded back against the pouch. Any residual heat from the sealing might encourage spotting, but as the seam lies along the pouch it forms a multi-layer fleece where the outer layer might not show the spots on the plural layers nearer the snus.
Despite advances in low-moisture snus and alterations to the location and type of heat seals, there remains a need in the art to provide improvements which will offer a snus product which offers ease of handling while also reducing the problem of spotted snus pouches.